Establishing a telephony session

ABSTRACT

Measures are provided for use in establishing a telephony session between first and second telephony devices in a telephony network. Telephony network equipment in the telephony network receives, from the first telephony device over a signalling link, a telephony session establishment request. The telephony network equipment receives, from the first telephony device over a data link that is separate to the signalling link, a message comprising data useable by the telephony network equipment to identify the second telephony device. The telephony network equipment correlates the received telephony session establishment request and the received message. The telephony network equipment transmits, to the second telephony device, a telephony session establishment request on the basis of the correlating. The first telephony device is associated with a multi-persona user having a first persona associated with a first telephony identifier and a second persona associated with a second telephony identifier.

CROSS REFERENCE TO RELATED APPLICATION(S)

This application is a continuation of U.S. patent application Ser. No.16/411,969, filed May 14, 2019, which is a continuation of U.S. patentapplication Ser. No. 16/035,229, filed Jul. 13, 2018, now issued as U.S.Pat. No. 10,498,903 B2 on Dec. 3, 2019, which claims the benefit under35 U.S.C. § 119(a) and 37 CFR § 1.55 to UK Patent Application No.1713859.5, filed on Aug. 30, 2018, the entire content of which isincorporated herein by reference.

BACKGROUND OF THE INVENTION Technical Field

The present disclosure relates to establishing a telephony session. Inparticular, but not exclusively, the present disclosure relates tomethods, apparatuses and computer programs for use in establishing atelephony session.

Background

A user of a telephony network may have multiple different personas. Apersona may be considered to be an identity, role or character adoptedby a user. For example, a multi-persona user may have a first, personalpersona and a second, business persona. There may be scenarios in whichthe multi-persona user wishes to conduct telephony in relation to bothpersonas using a single telephony user device, for example so that theuser need not carry both a personal telephony user device and a businesstelephony user device. There are several possible approaches toproviding multi-persona telephony services and various considerations tobe taken into account in using any such approach. Examples of suchconsiderations include, but are not limited to, call quality, ease ofcall setup, latency of call setup, reliability of call setup, andcomplexity of telephony user devices that can be used in suchapproaches.

SUMMARY

According to first embodiments, there is provided a method for use inestablishing a telephony session between first and second telephonydevices in a telephony network, the method comprising, at telephonynetwork equipment in the telephony network: receiving, from the firsttelephony device over a signalling link, a telephony sessionestablishment request; receiving, from the first telephony device over adata link that is separate to the signalling link, a message comprisingdata useable by the telephony network equipment to identify the secondtelephony device; correlating the received telephony sessionestablishment request and the received message; and transmitting, to thesecond telephony device, a telephony session establishment request onthe basis of said correlating, wherein the first telephony device isassociated with a multi-persona user having a first persona associatedwith a first telephony identifier and a second persona associated with asecond telephony identifier.

According to second embodiments, there is provided a method for use inestablishing a telephony session between first and second telephonydevices in a telephony network, the method comprising, at the firsttelephony device: transmitting, to telephony network equipment in thetelephony network over a signalling link, a telephony sessionestablishment request; transmitting, to the telephony network equipmentvia a data link that is separate to the signalling link, a messagecomprising data useable by the telephony network equipment to identifythe second telephony device; and conducting telephony with the secondtelephony device via the telephony session, the telephony session havingbeen established on the basis of the transmitted telephony sessionestablishment request and the transmitted message, wherein the firsttelephony device is associated with a multi-persona user having a firstpersona associated with a first telephony identifier and a secondpersona associated with a second telephony identifier.

Further features and advantages will become apparent from the followingdescription, given by way of example only, which is made with referenceto the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a schematic block diagram representing an example of atelephony network;

FIG. 2 shows a schematic block diagram representing another example of atelephony network;

FIG. 3 shows a sequence diagram representing an example of a method; and

FIG. 4 shows a sequence diagram representing another example of amethod.

DETAILED DESCRIPTION OF CERTAIN INVENTIVE EMBODIMENTS

Referring to FIG. 1, there is shown schematically an example of atelephony network 100.

A telephony network (also referred to as a ‘telephone network’) is atype of telecommunications network in which telephony sessions (alsoreferred to as ‘telephone calls’ or ‘calls’) can be established andtelephony can be conducted between two or more users of the telephonynetwork. Such users may be known as ‘entities’, ‘parties’, ‘subscribers’or ‘end users’. A telephony session may be established between a callingparty and a called party. A telephony session may involve a voice calland/or a video call.

In this example, the telephony network 100 comprises apparatuses in theform of first and second telephony devices 105, 110 and apparatus in theform of telephony network equipment 115. It will be appreciated that, inreality, a telephony network may comprise more telephony devices and/ormore telephony network equipment than in the example telephony network100.

The first and second telephony devices 105, 110 and/or the telephonynetwork equipment 115 may comprise one or more processors and one ormore memories. One or more computer programs comprisingcomputer-readable instructions may be stored in the one or morememories. The one or more processors may be configured to execute thecomputer-readable instructions and perform at least some of the methodsand techniques described herein as result.

In the examples described herein, the first and second telephony devices105, 110 are both telephony user devices (also referred to as‘endpoints’, ‘endpoint devices’ and ‘subscriber devices’), it beingunderstood that one or both of the first and second telephony devices105, 110 may not be telephony user devices. An example of a telephonydevice that is not a telephony user device is a voicemail server.Telephony user devices are used by users of the telephony network andmay take various different forms. Examples of telephony user devicesinclude, but are not limited to, mobile (also referred to as ‘cellular’)telephones, smartphones, tablet computing devices, laptop computingdevices, desktop computing devices, in-vehicle entertainment systems andsmart watches. In this specific example, the first telephony user device105 is associated with a first user and the second telephony user device110 is associated with a second, different user. In other examples, thefirst and second telephony user devices 105, 110 are associated with thesame user.

In this example, the first user (associated with the first telephonyuser device 105) is a multi-persona user. The first user has multiplepersonas, including first and second personas. The first user may havemore than two personas. For example, the first user may have a firstpersona and one or more additional personas including, at least, asecond persona. The first and second personas are associated with one ormore telephony service providers. A telephony service provider providesa telephony service to the first user. Examples of telephony serviceproviders include, but are not limited to, mobile network operators andnon-mobile network operators. The first and second personas of the firstuser may be associated with first and second, different telephonyservice providers respectively (for example a mobile network operatorand a non-mobile network operator respectively). Alternatively, thefirst and second personas of the first user may be associated with thesame telephony service provider as each other. The first user may have afirst account associated with the first persona and a second accountassociated with the second persona. Both accounts may be with the sametelephony service provider where the same telephony service provider isassociated with the first and second personas, or the first account maybe associated with the first telephony service provider and the secondaccount may be associated with the second telephony service providerwhere the first and second accounts are associated with first and secondtelephony service providers respectively. The first account, which isassociated with the first persona, may be associated with a firsttelephony identifier ID_(1A). The second account, which is associatedwith the second persona, may be associated with a second telephonyidentifier ID_(1B). Examples of telephony identifiers include, but arenot limited to, telephone numbers, telephony service usernames andSession Initiation Protocol (SIP) Uniform Resource Indicators (URIs).The first and second accounts may be associated with the same type oftelephony service, or may be associated with different types oftelephony services. Examples of such telephony services include, but arenot limited to, landline telephony services, mobile telephony services,mobile Voice over Internet Protocol (VoIP) telephony services andnon-mobile VoIP telephony services.

The first persona may be a personal persona and the second persona maybe a business persona. However, the first and second personas need notbe personal and business personas respectively. For example, the firstand second personas could both be personal personas, the first andsecond personas could both be business personas, the first persona maynot be a personal persona and the second persona may not be a businesspersona.

The first telephony user device 105 is associated with the firsttelephony identifier ID_(1A). For example, the first telephony userdevice 105 may be the primary device the first user uses for calls usingthe first account, with which the first telephony identifier ID_(1A) isassociated.

The second telephony user device 110 is associated with a furthertelephony identifier ID₂.

The telephony network equipment 115 may take various different forms. Insome examples, the telephony network equipment 115 is in the form of atelephony application server (TAS). A TAS is an entity in a telephonynetwork that carries out functions not directly related to routing ofmessages in the network. Examples of such functions include, but are notlimited to, automatic call forwarding functions and conference bridgefunctions. Where the telephony network 100 comprises an InternetProtocol Multimedia Subsystem (IMS) core, the TAS may be an IMS-TASlocated behind the IMS core. As such, the IMS core may be configuredwith a trigger such that processing at the IMS-TAS is invoked for atleast some telephony sessions involving the first user. Alternatively,the TAS may be a legacy (also referred to as a ‘non-IMS’) TAS, forexample where the telephony network 100 does not comprises an IMS core.An example of such a TAS is the MetaSphere® Multiservice TelephonyApplication Server (MTAS) available from Metaswitch Networks Ltd. Insome examples, the telephony network equipment 115 is in the form of agateway. A gateway is an entity in a telephony network that interfacesmultiple different networks that use different protocols. For example,the telephony network equipment 115 may be implemented as a gateway thatsits between a Public Switched Telephone Network (PSTN) and an IMS core.Implementing the telephony network equipment 115 as a gateway may allowthe telephony network equipment 115 to integrate more easily with an IMScore than would be the case with a TAS. The gateway may be able to workwith different types of telephony switch. The telephony networkequipment 115 may serve a public telephony network, in other words atelephony network that is accessible to the public. A public telephonynetwork differs from a private telephony network such as a corporatetelephony network, which only users associated with the corporation canaccess.

The telephony network equipment 115 is associated with a telephonynetwork equipment identifier ID_(TNE). The telephony network equipmentidentifier ID_(TNE) may, for example, be in the form of a telephonenumber, telephony service username or a SIP URI. The telephony networkequipment 115 may be associated with multiple telephony networkequipment identifiers. The telephony network equipment identifiers mayrelate to different geographical locations. For example, one telephonynetwork equipment identifier may be used when the first user is in ahome country and another telephony network equipment identifier may beused when the first user is roaming.

The telephony network equipment identifier ID_(TNE) may be apreconfigured identifier to be used by the first telephony user device105 in telephony session establishment requests when the first telephonyuser device 105 determines that the first user desires to establish thetelephony session with the second telephony user device 110 based on thesecond persona.

One or more telephony network equipment identifiers ID_(TNE) may bereserved for use by a given user of the telephony network 100, forexample the first user. For example, the first user may be associatedwith one or more telephony network equipment identifiers ID_(TNE) suchthat telephony session establishment requests directed to the one ormore telephony network equipment identifiers ID_(TNE) can be determinedto relate to the first user. As such, the telephony network equipment115 may be able to determine that a telephony session setup requestoriginates from the first user if the telephony session setup request isdirected to a telephony network equipment identifier ID_(TNE) associatedwith the first user, even if the telephony session setup request doesnot include other data identifying the first user (for example ifcalling party identification is withheld).

Alternatively, a given telephony network equipment identifier ID_(TNE)may be useable by several, for example all, users of the telephonynetwork 100. As such, fewer telephony network equipment identifierID_(TNE) may be reserved for the purposes described herein.

As indicated above, there are several possible approaches to providingmulti-persona telephony services and various related considerations. Inparticular, there are several possible approaches to providingmulti-persona telephony services in which the first user can conducttelephony in relation to the first and second personas using the firsttelephony user device 105, so that outgoing calls can be made to appearto be from the first or second persona and/or in which incoming callsmade in relation to the first or second persona can be received by thefirst telephony user device 105. In the examples described herein, it isassumed that one of the first user and the second user wishes to speakto the other of the first user and the second user and, as such, that atelephony session is to be established between the first telephony userdevice 105 and the second telephony user device 110.

One possible approach, for outgoing calls where the first user desiresto speak to the second user using the first telephony user device 105and the second persona, would be for the first telephony user device 105to transmit a telephony session establishment request with the calledparty identifier set as the further telephony identifier ID₂ and thecalling party identifier set as the second telephony identifier ID_(1B).This may be possible where, for example, the first account is associatedwith a first Subscriber Identity Module (SIM) card and the secondaccount is associated with a second SIM card and where the firsttelephony user device 105 is a dual-SIM telephony user device. However,dual-SIM telephony user devices may be relatively large and expensivecompared to single-SIM devices. Further, a dual-SIM telephony userdevice may not be suitable where the second account is associated with anon-mobile telephony service provider that does not issue SIM cards (forexample a VoIP service provider such as Skype™).

Another possible approach, for outgoing calls where the first userdesires to speak to the second user using the first telephony userdevice 105 and the second persona, would be for the first telephony userdevice 105 to append the further telephony identifier ID₂ to thetelephony network equipment identifier ID_(TNE) and to transmit atelephony session establishment request with the called party identifierset as a combined identifier ID_(TNE)+ID₂. As such, the furthertelephony identifier ID₂ would be signalled in-band with the telephonynetwork equipment identifier ID_(TNE). However, restrictions on thelength and format of called party identifiers in signalling flows (forexample within a PSTN) and the potential inability of the PSTN to routesuch called party identifiers mean that, in practice, such call setupattempts may not be effective.

Another possible approach, for outgoing calls where the first userdesires to speak to the second user using the first telephony userdevice 105 and the second persona, would be for the first telephony userdevice 105 to conduct telephony in relation to the first account using afirst connection, for example a circuit-switched telephony connection,and to conduct telephony in relation to the second account using asecond, separate connection, for example a packet-switched dataconnection. This may be effective where, for example, the first accountis associated with a mobile service provider and the second account isassociated with a non-mobile service provider (for example a VoIPtelephony service provider). For example, a native dialler function onthe first telephony user device 105 may be able to conductcommunications using the circuit-switched telephony connection andanother function on the first telephony user device 105, such as astandalone application and/or a function that integrates with the nativedialler function, may be able to conduct communications using thepacket-switched data connection. However, such an approach would rely onthe packet-switched data connection for transmission and reception ofvoice data. As such, the quality of the media would be dependent on theavailability and service quality of the packet-switched data connection,which may result in lower call quality than where a circuit-switchedtelephony connection is used.

Another possible approach, for outgoing calls where the first userdesires to speak to the second user using the first telephony userdevice 105 and the second persona, would be for the first telephony userdevice 105 to include a given symbol, such as the number ‘9’, in thecalled party identifier of a telephony session establishment requestwhen making a call in relation to the second persona using a connection(such as a circuit-switched telephony connection) associated with thefirst account. The first telephony user device 105 could automaticallyinclude the given symbol in outgoing telephony session establishmentrequests related to the second account such that the first user need notremember to do so manually. However, such an approach may be restrictedto implementations in which the service provider associated with thesecond account is the same as the service provider associated with thefirst account. This may not enable multi-persona telephony where, forexample, the service provider associated with the first account is amobile telephony service provider and the service provider associatedwith the second account is a non-mobile telephony service provider (forexample a VoIP service provider).

Another possible approach, for outgoing calls where the first userdesires to speak to the second user using the first telephony userdevice 105 and the second persona, would be for the first user to use acalling card service. The calling card service may allow the first userto make outgoing calls using the first account appear to be from thesecond account in a manner that is not integrated within the nativedialler function of the first telephony user device 105. To make such anoutgoing call, the first user would first dial an access phone numberassociated with the calling card operator. The first user would then bepresented with an Interactive Voice Response (IVR) menu via which theycan enter the further telephony identifier ID₂, as well as a PersonalIdentification Number (PIN). The user experience could be made moreseamless by having the native dialler function of the first telephonyuser device 105 dial the access phone number, pause, and then enter thefurther telephony identifier ID₂ automatically for example via dual-tonemulti-frequency (DTMF) signalling. However, use of a calling cardservice can result in an unacceptably long delay in setting up anoutgoing call. Further, calling cards may not offer support for handlingincoming calls, and not in a way in which an incoming call can bedistinguished as being associated with the second account.

Another possible approach, for outgoing calls where the first userdesires to speak to the second user using the first telephony userdevice 105 and the second persona, would be for the first telephony userdevice 105 to request callback from the telephony network equipment 115,via telephony signalling or via a separate data connection (for examplebased on Hypertext Transfer Protocol (HTTP) or HTTP Secure (HTTPS)). Thetelephony network equipment 115 would reject the incoming call if thetelephony signalling approach is used, or would process the callbackrequest if received via the separate data connection, and would transmita telephony session establishment request to the first telephony userdevice 105. The first telephony user device 105 would answer theincoming call from the telephony network equipment 115 and would providethe further telephony identifier ID₂ to the telephony network equipment115 in-band, for example via DTMF signalling. The telephony networkequipment 115 would then join the call legs it establishes with thefirst telephony user device 105 and the second telephony user device110, when the second telephony user device 110 accepts the call, toestablish the telephony session between the first and second telephonyuser devices 105, 110. However, as indicated above, providing thefurther telephony identifier ID₂ to the telephony network equipment 115via DTMF introduces a delay into the call establishment procedure.Further, such a solution may involve the use of an application separateto a native dialler application, may involve use of a Hosted PrivateBranch Exchange (HPBX) which may provide a limited feature set forcorporate users of a private telephony network only (as opposed toproviding services to users of a public telephony network), and may notallow for separation of voicemail for multi-persona users.

In one approach, for incoming calls where the second user desires tospeak to the first user based on the second persona of the first user,the telephony network equipment 115 receives an incoming telephonysession establishment request from the second telephony user device 110with the called party identifier set as the second telephony identifierID_(1B) and the calling party identifier set as the further telephonyidentifier ID₂. The telephony network equipment 115 would then set thecalling party identifier in a telephony session establishment request tothe first telephony user device 105 as a combination of the telephonynetwork identifier ID_(TNE) and the further telephony identifier ID₂,for example ID_(TNE)+ID₂. The first telephony user device 105 could thendetermine that the incoming call relates to the second persona on thebasis that the telephony session establishment request has been receivedfrom the telephony network equipment 115 and could extract the furthertelephony identifier ID₂ from the calling party identifier in thetelephony session establishment request. If it is known that the firstaccount does not have voicemail or any other automated service that mayanswer an incoming call and/or if it is acceptable for a voicemailsystem associated with the first account to be used for calls relatingto the second persona, then this may be an acceptable solution. However,where the first user desires to keep a separation between voicemailsrelating to the first and second personas, then such an approach may notbe acceptable, since the telephony network equipment 115 may not be ableto disambiguate between the first user manually accepting the telephonysession establishment request on the first telephony user device 105 andthe telephony session establishment request being automaticallyforwarded to a voicemail system associated with the first account whichthen automatically accepts the telephony session establishment request.

Measures (for example methods, apparatuses and computer programs) areprovided herein for use in establishing a telephony session between thefirst and second telephony user devices 105, 110 in the telephonynetwork 100.

A telephony session establishment request is transmitted to establish atelephony session 120 between the first telephony user device 105 andthe telephony network equipment 115. The telephony session establishmentrequest may take various different forms. For example, the telephonysession establishment request may be in the form of a SIP INVITEmessage. The telephony session establishment request may be transmittedby the first telephony user device 105 and received by the telephonynetwork equipment 115, for example for outgoing calls from the firsttelephony user device 105, or may be transmitted by the telephonynetwork equipment 115 and received by the first telephony user device105, for example for incoming calls to the first telephony user device105. The telephony session establishment request is transmitted over asignalling link. The signalling link may be a SIP signalling link orotherwise.

The telephony session establishment request may comprise data useable bya recipient of the telephony session establishment request (for examplethe first telephony user device 105 or the telephony network equipment115) to identify the first telephony identifier ID_(1A) and/or datauseable by a recipient of the telephony session establishment request(for example the first telephony user device 105 or the telephonynetwork equipment 115) to identify the telephony network equipmentidentifier ID_(TNE). Such data may be useable by entity other than thefirst telephony user device 105 or the telephony network equipment 115to identify the first telephony identifier ID_(1A) and/or the telephonynetwork equipment identifier ID_(TNE). An example of another such entityis a network node intermediate the first telephony user device 105 andthe telephony network equipment 115. For example, the intermediatenetwork node may receive data useable to identify the first telephonyidentifier ID_(1A) and may output the first telephony identifier ID_(1A)(or data useable to identify the first telephony identifier ID_(1A) asthe case may be).

The telephony session establishment request may not comprise datauseable by a recipient of the telephony session establishment request(for example the first telephony user device 105 or the telephonynetwork equipment 115) to identify the first telephony identifierID_(1A) where the recipient can identify the first telephony identifierID_(1A) in another manner and/or does not need to identify the firsttelephony identifier ID_(1A). For example, the telephony networkequipment 115 may be able to identify the first telephony identifierID_(1A) from the particular telephony network identifier ID_(TNE) used,for example as a called party identifier, if that particular telephonynetwork identifier ID_(TNE) is associated with the first telephonyidentifier ID_(1A).

The telephony session establishment request may not comprise datauseable by a recipient of the telephony session establishment requestdata useable by a recipient of the telephony session establishmentrequest (for example the first telephony user device 105 or thetelephony network equipment 115) to identify the telephony networkequipment identifier ID_(TNE) where the recipient can identify thetelephony network equipment identifier ID_(TNE) in another manner and/ordoes not need to identify the telephony network equipment identifierID_(TNE). For example, the first telephony user device 105 may bephysically connected to a particular port of the telephony networkequipment 115 such that the first telephony user device 105 need notinclude the telephony network equipment identifier ID_(TNE) in thetelephony session establishment request, for example as a called partyidentifier.

A message is transmitted via a data link 125. The data link 125 isbetween the first telephony user device 105 and the telephony networkequipment 115 and is separate to the signalling link over which thetelephony session establishment request is transmitted. The data link125 may be established before the telephony session 120 is established.The data link 125 may, for example, be based on SIP, HTTP, HTTPS etc.The message may be transmitted by the first telephony user device 105and received by the telephony network equipment 115, for example foroutgoing calls from the first telephony user device 105, or may betransmitted by the telephony network equipment 115 and received by thefirst telephony user device 105, for example for incoming calls to thefirst telephony user device 105. The message may comprise data useableby the recipient of the message (for example the first telephony userdevice 105 or the telephony network equipment 115) to identify thefurther telephony identifier ID₂ (for example the further telephonyidentifier ID₂ itself). In other examples, the recipient may be able todetermine or infer the further telephony identifier ID₂ in anothermanner, for example if calls involving a further telephony identifierID₂ have historically been made at the same or substantially the sametime of day over a given period. The message may comprise other data.Examples of such other data include, but are not limited to, datauseable by the recipient of the message to identify the first telephonyidentifier ID_(1A) (for example the first telephony identifier ID_(1A)itself), data useable by the recipient of the message to identify thesecond telephony identifier ID_(1B) (for example the second telephonyidentifier ID_(1B) itself) and data useable by the recipient of themessage to identify the telephony network equipment identifier ID_(TNE)(for example the telephony network equipment identifier ID_(TNE)itself). The message is transmitted via the data link 125, out-of-band(also referred to as ‘over-the-top (OTT)’) in relation to the signallinglink. The message comprises data that can be used to establish atelephony session between the first and second telephony user devices105, 110 (even if such a telephony session is not in fact established)and, as such, may be considered to be telephony session setupinformation. However, such telephony session setup information relatesto a telephony session between the first and second telephony userdevices 105, 110 whereas the telephony session establishment requesttransmitted between the first telephony user device 105 and thetelephony network equipment 115 relates to the telephony session 120between the first telephony user device 105 and the telephony networkequipment 115.

As explained above, a telephony session establishment request istransmitted or received over a signalling link and a message istransmitted or received over a data link 125 that is separate to thesignalling link. The telephony session establishment request may betransmitted (or received) before, after, or at the same time as themessage is transmitted (or received). As such, unless expresslyindicated otherwise, references to transmitting (or receiving) atelephony session establishment request over a signalling link and totransmitting (or receiving) a message over a data link that is separateto the signalling link, should be understood to include these differentpossibilities. Further, in some examples, an apparatus transmits themessage in response to receiving another message (for example fromapparatus to which the message is transmitted). In other examples, anapparatus does not transmit the message in response to receiving anothermessage (for example from apparatus to which the message istransmitted).

In the case of incoming calls to the first telephony user device 105,the first telephony user device 105 can use the data comprised in thetelephony session establishment request and/or the data comprised in themessage to determine that the telephony session establishment requestrelates to the second persona, for example on the basis of the telephonysession establishment request having the telephony network equipmentidentifier ID_(TNE) as the calling party identifier, and to identify thecaller, namely the second user, to the first user, for example on thebasis of inclusion of data useable to identify the further telephonyidentifier ID₂ in the message.

In the case of outgoing calls from the first telephony user device 105,the telephony network equipment 115 can use the data comprised in thetelephony session establishment request and the data comprised in themessage to determine that the telephony session establishment requestrelates to the second persona, for example on the basis of the telephonysession establishment request having the telephony network equipmentidentifier ID_(TNE) as the called party identifier, and to identify theparty with which the first user wishes to speak, namely the second user,for example on the basis of the inclusion of data useable to identifythe further telephony identifier ID₂ in the message.

As such, in accordance with examples described herein, carrier-qualityaudio may be provided for both incoming and outgoing calls formulti-persona users that have an account with a mobile network operator.For example, calls relating to both the first and second personas may beconducted using a cellular, circuit-switched connection where the userhas an account with a mobile network operator. Further, non-mobiletelephony service providers may still provide carrier-quality audio bymaking use of a cellular connection. Automated setup of outgoing callsmay also be provided, in contrast to use of some calling card serviceswhich involve user interaction with an IVR to enter a target phonenumber. As will be described in more detail below, the likelihood ofcalls associated with the second persona (such as non-personal, businesscalls) being sent to a voicemail service associated with the firstpersona of the user (such as a voicemail system associated with apersonal account) may be reduced. Such features may enhance userexperience. Examples described herein may provide multi-persona unifiedcommunications (UC) solutions for both mobile operators and non-mobileoperators. As such, examples described herein can provide mobile-VoIPconverged UC.

Referring to FIG. 2, there is shown schematically another example of atelephony network 200. The telephony network 200 comprises some elementsthat are the same as, or are similar to, elements in the exampletelephony network 100 described above with reference to FIG. 1. Suchelements are indicated in FIG. 2 using the same reference signs as thoseused in FIG. 1, but incremented by 100.

In this example, the telephony network 200 comprises a mobile network230, a PSTN 235 and an alternative network 240. In this example, thetelephony session establishment request is transmitted via the mobilenetwork 230, the PSTN 235, and the alternative network 240. Whether thetelephony session establishment request is transmitted via the mobilenetwork 230, and then via the PSTN 235, and then via the alternativenetwork 240 or vice versa depends on whether the telephony sessionestablishment request is for an incoming call or for an outgoing callfrom the perspective of the first telephony user device 205. A data link225 can be established between the first telephony user device 205 andthe telephony network equipment 215.

The telephony network 200 may be used to provide multi-persona telephonyfor the first user via a single cellular connection associated with thefirst persona. In particular, the first user may be able to make andreceive calls in relation to a second account associated with thealternative network 240 using the cellular connection related to thefirst account. As explained above, the first and second accounts may beprovided by the same or different telephony service provider networks.As such, multiple accounts may be consolidated onto one telephony userdevice.

Referring to FIG. 3, there is shown an example method 300 for use inestablishing a telephony session between first and second telephony userdevices. In this example, the method 300 is performed in the examplenetwork 100 described above with reference to FIG. 1. The method 300 mayhowever be performed in the example network 200 described above withreference to FIG. 2.

In this example, the method 300 corresponds to the first user making anoutgoing call to the second telephony user device 110.

At item S3 a, the first telephony user device 105 determines that thefirst user desires to establish the telephony session with the secondtelephony user device 110 based on the second persona. The firsttelephony user device 105 may make such a determination based on one ormore factors. An example factor is the location of the first telephonyuser device 105 being associated with the second persona, for examplethe second persona being a business persona and the first user being ata known work location. Another example factor is the second user beingassociated with the second persona, for example the second persona beinga business persona and the second user being a business contact. Anotherexample factor is the first user initiating a telephony sessionestablishment using a predetermined function on the first telephony userdevice 105 associated with the second persona, for example the secondpersona being a business persona and the predetermined function being abusiness dialler function. Another example factor is the time or dayand/or day of week at which the first user wishes to establish thetelephony session being associated with the second persona, for examplethe second persona being a business persona and the first userinitiating the telephony session during working hours. Another examplefactor is the inclusion of a predetermined symbol in a telephonyidentifier provided for the second user, for example the presence of thenumber ‘9’ at the start of the telephony identifier provided for thesecond user to indicate that the second user is associated with thesecond persona. Another example factor is the second user being in agroup of contacts in an address book on the first telephony user device105 associated with the second persona, for example the second personabeing a business persona and the second user being in a business contactaddress book. Another example factor is the first telephony user device105 being in an operating mode associated with the second persona, forexample the second persona being a business persona and the firsttelephony user device 105 being in a business operating mode.

At item S3 b, the first telephony user device 105 transmits a messagevia the data link 125 that is separate to the signalling link over whichthe telephony session establishment request is transmitted at item S3 cbelow. The data link 125 being separate to the signalling link does notimply that the telephony session 120 has been or will be established.The message comprises data useable to identify the further telephonyidentifier ID₂. The data useable to identify the further telephonyidentifier ID₂ may comprise the further telephony identifier ID₂ itself.Alternatively or additionally, the telephony network equipment 115 maybe able to map the data useable to identify the further telephonyidentifier ID₂ to the further telephony identifier ID₂. The message maycomprise data useable to identify the first telephony identifier ID_(1A)(for example the first telephony identifier ID_(1A) itself), and/or thetelephony network equipment 115 may be able to determine that themessage originates from the first telephony user device 105 and/orrelates to the first user in another manner (for example based on otherdata in the message or data external to the message). The message ofitem S3 b may indicate that the first user wishes to call the seconduser on the basis of the second persona. The second telephony identifierID_(1B) associated with the second persona may already be known to thetelephony network equipment 115. As such, the second telephonyidentifier ID_(1B) may not explicitly be included in the message. Forexample, the relationship between the first user and the second personaand/or the second telephony identifier ID_(1B) might have been declaredby the first user or by operator configuration (and not under thecontrol of the first user), for example long prior to call setup. Theoperator configuration approach may be used to deny the first user theability to do arbitrary identity spoofing.

The telephony network equipment 115 may transmit an acknowledgementmessage (not shown in FIG. 3) to the first telephony user device 105 toconfirm receipt of the message. In response to receiving theacknowledgement message from the telephony network equipment 115, thefirst telephony user device 105 can determine that the telephony networkequipment 115 is able to note the entity with whom the first user wishesto speak. The acknowledgement message could provide the first telephonyuser device 105 with information useable subsequently in establishingthe telephony session. For example, the acknowledgement message couldprovide the first telephony user device 105 with data useable toidentify the telephony network equipment identifier ID_(TNE) (forexample the telephony network equipment identifier ID_(TNE) itself). Assuch, the telephony network equipment 115 may be able to obtain thetelephony network equipment identifier ID_(TNE) on-demand.

At item S3 c, the first telephony user device 105 transmits a telephonysession establishment request over the signalling link. The telephonysession establishment request comprises a request to establish thetelephony session 120 between the first telecommunications device 105and the telecommunications network equipment 115. The telephony session120 may or may not, in fact, be established between the firsttelecommunications device 105 and the telecommunications networkequipment 115 at this stage. The telephony session establishment requestmay comprise data useable to identify the first telephony identifierID_(1A) (for example the first telephony identifier ID_(1A) itself)and/or data useable to identify the telephony network equipmentidentifier ID_(TNE) (for example the telephony network equipmentidentifier ID_(TNE) itself). The telephony session establishment requestmay, for example, be transmitted from the first telephony user device105 to the telephony network equipment 115 via a mobile network, a PSTNand an IMS core. The telephony user device 105 may display the furthertelephony identifier ID₂ and/or data identifying the second user,instead of the telephony network equipment identifier ID_(TNE), via anin-call user interface (UI). As such, the involvement of the telephonynetwork equipment 115 in establishing the telephony session may betransparent to the first user.

Although in this example, the message of item S3 b is transmitted beforethe telephony session establishment request of item S3 c, severalalternative approaches could be taken. For example, the telephonysession establishment request of item S3 c may be transmitted prior to,or at the same time as, the message of item S3 b. The telephony networkequipment 115 may receive the telephony session establishment request ofitem S3 c and may await the message of item S3 b to determine that thetelephony session is to be established with the second telephony userdevice 110. The message of item S3 b may be transmitted proactively bythe first telephony user device 105 or may be transmitted reactively inresponse to the first telephony user device 105 receiving a message fromthe telephony network equipment 115 requesting data identifying thecalled party. The telephony network equipment 115 may be able to requestsuch data from the first telephony user device 105 over the data linkvia a push notification (for example using the Apple Push NotificationService (APNs)), or via a return path that has been built up by thefirst telephony user device 105 previously registering (andre-registering as it moved around), as is done in SIP.

At item S3 d, the telephony network equipment 115 correlates datacomprised in the telephony session establishment request received fromthe first telephony user device 105 at item S3 b with data comprised inthe message received from the first telephony user device 105 at item S3c and determines that the first user desires to establish the telephonysession with the second telephony user device 110 based on the secondpersona. For example, where the message transmitted via the dataconnection 125 and the telephony session establishment request comprisethe first telephony identifier ID_(1A), the telephony network equipment115 can correlate the first telephony identifier ID_(1A) comprised inthe message with the first telephony identifier ID_(1A) comprised in thetelephony session establishment request to determine that both relate tothe first user, and identify the called party based on the inclusion ofthe second telephony identifier ID₂ (or data useable to identify thesecond telephony identifier ID₂) in the message. The correlationperformed by telephony network equipment 115 in relation to thetelephony session establishment request of item S3 b and the message ofitem S3 c may be temporal, for example where the telephony sessionestablishment request and the message can be assumed to be from the samesource if they are received within a predetermined time period of eachother. This may be possible where the telephony network 100 includes arelatively small number of users and/or when calls in the telephonynetwork 100 are relatively infrequent such that the likelihood of twocalls being made at the same time is sufficiently low.

At item S3 e, the telephony network equipment 115 transmits an outgoingtelephony session establishment request to the second telephony userdevice 110 based on the telephony session establishment request receivedfrom the first telephony user device 105 at item S3 b and the messagereceived from the first telephony user device 105 at item S3 c. Theoutgoing telephony session establishment request may comprise datauseable to identify the further telephony identifier ID₂ (for examplethe further telephony identifier ID₂ itself) and/or data useable toidentify the second telephony identifier ID_(1B) (for example the secondtelephony identifier ID_(1B) itself). The telephony network equipment115 may transmit the outgoing telephony session establishment request tothe second telephony user device 110 via an IMS core. Originating callservices provided by the IMS core may therefore be invoked.

At item S3 f, a telephony session is established between the first andsecond telephony user devices 105, 110. Voice and/or video data may forexample be communicated via the telephony session.

In some examples, where the first telephony user device 105 determines,at item S3 a, that the multi-persona user desires to establish thetelephony session with the second telephony user device 110 based on thefirst persona (as opposed to the second persona), the first telephonyuser device 105 conducts telephony session establishment in aconventional manner, for example by transmitting a telephony sessionestablishment request with the calling party identifier being the firsttelephony identifier ID_(1A) and the called party identifier being thefurther telephony identifier ID₂, rather than the called partyidentifier being the telephony network equipment identifier ID_(TNE).

In some examples, where the first telephony user device 105 is unable,at item S3 b, to transmit the message via the data link 125 (for examplewhere there is insufficient data connectivity), the first telephony userdevice 105 provides the first user with an option to establish thetelephony session with the second user on the basis of the first personainstead of on the basis of the second persona. In other examples, wherethe first telephony user device 105 is unable, at item S3 b, to transmitthe message via the data link 125, the first telephony user device 105automatically establishes the telephony session with the second user onthe basis of the first persona instead of on the basis of the secondpersona. The first telephony user device 105 may establish the telephonysession automatically in that the first telephony user device 105 maynot provide the first user with an option to establish the telephonysession with the second user on the basis of the first persona and/ormay not require user input in order to establish the telephony sessionwith the second user on the basis of the first persona. As such, afallback mechanism is provided to allow the first user to speak to thesecond user, for example in response to predetermined user input orautomatically.

In this example, the decision about which persona to use for a telephonysession is made on the first telephony user device 105, for exampleautomatically and/or by the user selecting a preferred persona manually.Additionally or alternatively, the decision about which persona to usecould be made by the telephony network equipment 115. For example, thefirst telephony user device 105 could direct all outgoing telephonysession establishment requests to the telephony network equipment 115and the telephony network equipment 115 could decide which persona touse, either autonomously or based on feedback from the first telephonyuser device 105 and/or the first user.

As such, for outgoing calls, the user dials the further telephonyidentifier ID₂, for example using a native dialler function on the firsttelephony user device 105, or using a predetermined function (such as asoftware application) on the first telephony user device 105 that thefirst user uses for outgoing calls related to the second persona. Anintercepting function on the first telephony user device 105 interceptsthe outgoing call. The intercepting function may be separate from thenative dialler function. The intercepting function may be part of thepredetermined function that the first user uses for outgoing callsrelated to the second persona. The intercepting function transmits themessage to the telephony network equipment 115 via the data link 125 toindicate that the first user wishes to dial the second user having thefurther telephony identifier ID₂. Examples described herein may make useof Android ConnectionService to place calls using a native dialler.Integration with Android for Work may provide separation of multiplepersonas on a device. Instead of transmitting the telephony sessionestablishment request with the further telephony identifier ID₂ as thecalled party identifier, the first telephony user device 105 places anoutgoing call to the telephony network equipment 115 over the signallinglink that is separate from the data link 125. The telephony networkequipment 115 receives the call request from the first telephony userdevice 105, may correlate the incoming caller identifier, namely thefirst telephony identifier ID_(1A), with the second telephony identifierID_(1B) associated with the first user and with the message received viathe data link 125 to find out that the first user is trying to call thefurther telephony identifier ID₂ and initiates a new call to the furthertelephony identifier ID₂. The telephony network equipment 115 may jointhe two legs of the telephony session, namely the first telephonysession leg between the first telephony user device 105 and thetelephony network equipment 115 and the second telephony session legbetween the telephony network equipment 115 and the second telephonyuser device 110, such that the telephony session is established betweenthe first telephony user device 105 and the second telephony user device110.

Referring to FIG. 4, there is shown an example of a method 400 for usein establishing a telephony session between first and second telephonyuser devices. In this example, the method 300 is performed in theexample network 100 described above with reference to FIG. 1. The method300 may however be performed in the example network 200 described abovewith reference to FIG. 2.

In this example, the method 400 corresponds to the first user receivingan incoming call from the second telephony user device 110.

The first telephony user device 105 may periodically register with thetelephony network equipment 115 and/or another entity in the telephonynetwork 100. The first telephony user device 105 may, for example,provide the first and/or second telephony identifiers ID_(1A), ID_(1B)in intermittent registration messages.

At item S4 a, the telephony network equipment 115 receives an incomingtelephony session establishment request originating from the secondtelephony user device 110. In this specific example, the incomingtelephony session establishment request comprises the further telephonyidentifier ID₂ as a calling party identifier and the second telephonyidentifier ID_(1B) as a called party identifier. The telephony networkequipment 115 may receive the telephony session establishment requestfrom an entity other than the second telephony user device 110. Forexample, the telephony network equipment 115 may receive the telephonysession establishment request from an IMS core, a SIP Registrar, etc. Insome examples, the telephony network equipment 115 registers with a SIPRegistrar as an endpoint for calls to the second telephony identifierID_(1B). One or more other devices may also be registered with the SIPRegistrar as an endpoint for calls to the second telephony identifierID_(1B). As such, calls to the second telephony identifier ID_(1B) maybe forked by the SIP Registrar to endpoints registered against thesecond telephony identifier ID_(1B).

At item S4 b, the telephony network equipment 115 maps the secondtelephony identifier ID_(1B) comprised in the incoming telephony sessionestablishment request to the first telephony identifier ID_(1A). Forexample, the telephony network equipment 115 may comprise a table inwhich the first telephony identifier ID_(1A) is stored in associationwith the second telephony identifier ID_(1B). In some examples, theincoming telephony session establishment request may comprise datauseable by the telephony network equipment 115 to identify the secondtelephony identifier ID_(1B), where such data may or may not comprisethe second telephony identifier ID_(1B) itself.

At item S4 c, the telephony network equipment 115 transmits a telephonysession establishment request to establish the telephony session 120between the first telephony user device 105 and the telephony networkequipment 115 via the signalling link. The telephony session 120 may ormay not be established between the first telephony user device 105 andthe telephony network equipment 115 at this stage. For example, thetelephony network equipment 115 may hold off establishing the telephonysession 120 until one or more predetermined events has occurred, asexplained in more detail below. In this specific example, the telephonysession establishment request comprises the first telephony identifierID_(1A) and the telephony network equipment identifier ID_(TNE). Thetelephony network equipment 115 may transmit a telephony sessionestablishment request to one or more further devices associated with thefirst user. For example, the first user may have one or more devices(such as SIP devices) registered in association with the first telephonyidentifier ID_(1A) and/or the second telephony identifier ID_(1B). Theone or more devices may, for example, include a VoIP device (such as asmart business phone). In such cases, mobile-VoIP convergence may beprovided.

At item S4 d, the first telephony user device 105 transmits anoriginating entity identification request to the telephony networkequipment 115 via the data link. The originating entity identificationrequest relates to the telephony session establishment request receivedby the first telephony user device 105 from the telephony networkequipment 115 at item S4 c. In this example, the originating entityidentification request serves as a lookup to identify the calling partyprior to the first telephony user device 105 ringing to alert the firstuser to the incoming call. The originating entity identification requestmay, for example, comprise the first telephony identifier ID_(1A) and/orthe second telephony identifier ID_(1B).

At item S4 e, the telephony network equipment 115 transmits, in responseto receiving the originating entity identification request at item S4 d,a message to the first telephony user device 105 via the data link 125.In this specific example, the message comprises the further telephonyidentifier ID₂.

In other examples, the telephony network equipment 115 proactivelytransmits the message of item S4 e to the first telephony user device105 without waiting for, or needing to receive, the originating entityidentification request from the first telephony user device 105. Forexample, although the telephony session establishment request of item S4c is transmitted before the message of S4 e in this example, alternativeapproaches are possible. For example, the message of S4 e could betransmitted to the first telephony user device 105 prior to, or at thesame time as, the telephony session establishment request of item S4 cbeing transmitted. As such, the originating entity identificationrequest may not be transmitted at item S4 d, since the first telephonyuser device 105 may already have been able to identify the callingparty. However, the first telephony user device 105 may transmit anacknowledgement to the message of S4 e in such an approach, which wouldthen trigger the telephony network equipment 115 to send the telephonysession establishment request of item S4 c.

At item S4 f, the first telephony user device 105 provides (for exampledisplays) the further telephony identifier ID₂ and/or originating entityidentification data based on the further telephony identifier ID₂ (forexample a name of the second user) to the first user, for example via anin-call UI, in response to the receiving of the message by the firsttelephony user device 105 from the telephony network equipment 115 atitem S4 e. In some examples, the first telephony user device 105 doesnot display the telephony network equipment identifier ID_(TNE) at thisstage.

At item S4 g, the first telephony user device 105 transmits to thetelephony network equipment 115, via the signalling link, an acceptancemessage indicating acceptance of the telephony session establishmentrequest received by the first telephony device 105 from the telephonynetwork equipment 115 at item S4 c.

At item S4 h, the first telephony user device 105 transmits to thetelephony network equipment 115, via the data link 125, a furtheracceptance message indicating acceptance of the telephony sessionestablishment request received by the first telephony device 105 fromthe telephony network equipment 115 at item S4 c. The acceptance messagemay be transmitted in response to the first user manually accepting therequest to establish the telephony session following the provision ofthe further telephony identifier ID₂ and/or the originating entityidentification data to the multi-persona user at item S4 f. The furtheracceptance message may, for example, comprise the first telephonyidentifier ID_(1A) and/or the second telephony identifier ID_(1B).

In some examples, it may be undesirable for an incoming call associatedwith the second persona to be sent to a voicemail system associated withthe first persona. This may occur if, for example, the first user isuncontactable or if they do not answer the incoming call. In someexamples, it may not be possible to determine from the acceptancemessage of item S4 g whether the call has been answered by themulti-persona user or by a voicemail system. The further acceptancemessage of item S4 h may be used to indicate that the first user, ratherthan another system (such as a voicemail system) or another user (if thecall were forwarded by the first telephony user device 105), hasanswered the call. Where the first account of the first user is knownnot to have a terminating voicemail system, processing associated withthe further acceptance message of item S4 h may be omitted for incomingcalls.

Further, if the user has no data link connectivity when they receivedthe call, their phone would ring, but they would be unable to send thefurther acceptance message of item S4 h and the call may not connect.The originating entity identification request of item S4 d may be usedto verify that the first telephony user device 105 does indeed have datalink connectivity, making the chance of the user experiencing such anon-connecting call negligible.

At item S4 i, the telephony network equipment 115 determines whetherboth the acceptance message of item S4 g and the further acceptancemessage of item S4 h have been received. In this specific example, thetelephony network equipment 115 only establishes the telephony sessionbetween the first and second telephony user devices 105, 110 in responseto receiving both the acceptance message of item S4 g and the furtheracceptance message of item S4 h. In such examples, if the telephonynetwork equipment 115 only receives the acceptance message of item S4 gand not also the further acceptance message of item S4 h, then thetelephony network equipment 115 does not establish the telephony sessionbetween the first and second telephony user devices 105, 110. This mayoccur when, for example, the call is forwarded to a voicemail system butthe first user has not manually accepted the call on the first telephonyuser device 105. In such cases, where the further acceptance message ofitem S4 h is not received, the telephony network equipment 115 maytransmit a cancellation message to the first telephony user device 105to cause the telephony session establishment procedure to be terminated.The cancellation message may, for example, be a SIP BYE message. Wherethe telephony network equipment 115 receives the telephony sessionestablishment request of item S4 a from a SIP Registrar, the telephonynetwork equipment 115 may transmit a message to the SIP Registrar toindicate that the call has not been answered. The message to the SIPRegistrar may, for example, be a SIP 4xx message. In such cases, wherethe SIP Registrar had forked the incoming call to another deviceassociated with the first user, and where the first user had acceptedthe call on the other device, the telephony session may be establishedbetween the second telephony user device 110 and the other device. Inother examples, the telephony network equipment 115 may establish thetelephony session between the first and second telephony user devices105, 110 even if the further acceptance message of item S4 h has notbeen received, for example if the first telephony device 105 is notconfigured to transmit such further acceptance messages.

At item S4 j, assuming the acceptance message of item S4 g and thefurther acceptance message of item S4 h are both received, the telephonynetwork equipment 115 establishes the telephony session between thefirst and second telephony user devices 105, 110. Where, at item S4 c,the telephony network equipment 115 transmitted the telephony sessionestablishment request to one or more further devices associated with thefirst user, the telephony network equipment 115 may transmit one or morecancellation requests to the one or more further devices where the firstuser has accepted the call on the first telephony user device 105. Wherethe telephony network equipment 115 receives the telephony sessionestablishment request of item S4 a from a SIP Registrar, the telephonynetwork equipment 115 may transmit an acceptance message to the SIPRegistrar. The acceptance message may, for example, be a SIP 200 OKmessage. The SIP Registrar may then send a cancellation message to anyother devices to which the SIP Registrar sent a telephony sessionestablishment request, on the basis that the call has been accepted byanother device.

As such, for incoming calls to the second telephony identifier ID_(1B),the telephony network equipment 115, which serves the second telephonyidentifier ID_(1B), receives the call. A multi-persona function istriggered at the telephony network equipment 115. The telephony networkequipment 115 may fork the call by sending an incoming telephony sessionestablishment request with the called party identifier being the firsttelephony identifier ID_(1A) and the calling party identifier being thetelephony network equipment identified ID_(TNE). The first telephonyuser device 105 receives the call and identifies the telephony networkequipment identified ID_(TNE) in the caller ID. In some examples, thefunction handling the call on the first telephony user device 105 doesnot allow the first telephony user device 105 to ring at this stage.Instead, the function sends an originating entity identification requestto the telephony network equipment 115 to determine the identity of thecalling party. The originating entity identification request istransmitted via the data link 125. In response to receiving dataidentifying the calling party from the telephony network equipment 115,the first telephony user device 105 displays the further telephonyidentifier ID₂ and/or identification data associated with the seconduser. In some examples, the telephony user device 105 does not displaythe telephony network equipment identifier ID_(TNE). In conjunction withdisplaying the further telephony identifier ID₂ and/or the associatedidentification data, the first telephony user device 105 rings to alertthe first user to the incoming call.

References herein to first data being communicated “in-band” withrespect to second data are intended to cover the first and second databeing transmitted in relation to the same link (for example a signallinglink or a data link), during session setup and/or after a session isestablished. References herein to first data being communicated“out-of-band” or “OTT” with respect to second data are intended to coverthe first and second data being transmitted in relation to differentlinks (for example a signalling link and a data link), during sessionsetup and/or after a session is established.

The above are to be understood as illustrative examples. Furtherexamples are envisaged.

Examples described above relate to establishing a telephony sessionbetween the first and second telephony user devices. Other examples mayrelate to enabling another type of telecommunication to be conductedbetween the first and second telephony user devices. Examples of othertypes of telecommunication include, but are not limited to, ShortMessaging Service (SMS) messaging and Multimedia Messaging Service (MMS)messaging. In such other examples, the first user may be able to sendand/or receive SMS and/or MMS messages in relation to multiple differentpersonas using a single telephony user device. As such, various measures(for example methods, apparatuses and computer programmes) are providedfor use in enabling first and second telephony user devices to conducttelecommunications in a telephony network. Telecommunications data (forexample an SMS message or an MMS message) is transmitted or received viaa first connection (for example a circuit-switched telephony connection)between the first telephony user device and telephony network equipmentin the telephony network. A message is transmitted or received via asecond connection (for example a packet-switched data connection) thatis between the first telephony user device and telephony networkequipment and that is separate to the first connection.

Examples are described above in which acknowledgement messages aretransmitted. As an alternative to use of acknowledgment messages, asmall delay could be applied with predetermined failure behaviour usedas needed.

It is to be understood that any feature described in relation to any oneexample may be used alone, or in combination with other featuresdescribed, and may also be used in combination with one or more featuresof any other of the examples, or any combination of any other of theexamples. Furthermore, equivalents and modifications not described abovemay also be employed without departing from the scope of the invention,which is defined in the accompanying claims.

What is claimed is:
 1. A method for use in establishing a telephonysession between first and second telephony devices in a telephonynetwork, the method comprising, at the first telephony device: receivinga telephony session establishment request from telephony networkequipment in the telephony network via a signalling link; determiningwhether or not a user of the first telephony device has accepted thereceived telephony session establishment request; in response todetermining that the user of the first telephony device has accepted thereceived telephony session establishment request, transmitting anacceptance message to the telephony network equipment via a data linkthat is separate to the signalling link, the acceptance messageindicating acceptance of the received telephony session establishmentrequest by the user of the first telephony device; and in response todetermining that the user of the first telephony device has not acceptedthe received telephony session establishment request, performing apredetermined action.
 2. The method of claim 1, wherein thepredetermined action comprises not transmitting an acceptance messagevia the data link.
 3. The method of claim 1, wherein the telephonysession is established via a cellular network controlled by a cellularnetwork operator.
 4. The method of claim 3, wherein: the data link isestablished via the cellular network; and/or the telephony networkequipment is controlled by a service provider other than said cellularnetwork operator.
 5. The method of claim 1, wherein the telephonynetwork comprises an Internet Protocol Multimedia Subsystem (IMS) core,wherein the telephony network equipment is a telephony applicationserver, and wherein the IMS core is configured with a trigger wherebyprocessing by the telephony network equipment is invoked for at leastsome telephony sessions involving the user of the first telephonydevice.
 6. The method of claim 1, wherein the telephony networkcomprises a Public Switched Telephony Network (PSTN), and an IMS core,and wherein the telephony network equipment is a gateway located betweenthe PSTN and the IMS core in the telephony network.
 7. The method ofclaim 1, wherein the telephony network equipment serves a publictelephony network.
 8. The method of claim 1, wherein establishing thetelephony session between the first and second telephony devicesinvolves the telephony network equipment causing a first telephonysession leg to be established between the first telephony device and thetelephony network equipment and a second telephony session leg to beestablished between the second telephony device and the telephonynetwork equipment.
 9. The method of claim 1, wherein the first telephonydevice is associated with a multi-persona user having a first personaassociated with a first telephony identifier and a second personaassociated with a second telephony identifier.
 10. The method of claim9, wherein the received telephony session establishment requestcomprises the first telephony identifier and/or a calling partyidentifier associated with the telephony network equipment.
 11. Themethod of claim 1, comprising transmitting an originating entityidentification request to the telephony network equipment via the datalink.
 12. The method of claim 11, wherein the originating entityidentification request is transmitted before said determining
 13. Themethod of claim 1, comprising receiving an originating entityidentification message from the telephony network equipment via the datalink.
 14. The method of claim 13, wherein the originating entityidentification message: is received before said determining; and/orcomprises a further telephony identifier associated with the secondtelephony device.
 15. The method of claim 1, comprising transmitting anacceptance message to the telephony network equipment via the signallinglink, the acceptance message transmitted via the signalling linkindicating acceptance of the received telephony session establishmentrequest.
 16. A method for use in establishing a telephony sessionbetween first and second telephony devices in a telephony network, themethod comprising, at telephony network equipment in the telephonynetwork: receiving a telephony session establishment request from thesecond telephony device; transmitting a telephony session establishmentrequest based on the received telephony session establishment request tothe first telephony device via a signalling link; determining whether ornot an acceptance message indicating acceptance of the transmittedtelephony session establishment request by a user of the first telephonydevice has been received from the first telephony device via a data linkthat is separate to the signalling link; in response to determining thatthe acceptance message has been received, causing the telephony sessionto be established between the first and second telephony device; and inresponse to determining that the acceptance message has not beenreceived, performing a predetermined action.
 17. The method of claim 16,wherein the performing of a predetermined action comprises causing thetelephony session not to be established between the first and secondtelephony devices.
 18. The method of claim 16, comprising holding upestablishment of the telephony session until the acceptance message isreceived from the first telephony device.
 19. The method of claim 16,wherein the acceptance message indicates that the telephony session hasbeen accepted by the user of the first telephony device rather than byanother entity.
 20. The method of claim 19, wherein the other entitycomprises a voicemail system.